feat: Add C implementation `math/base/special/log10f` by InFiNiTy0639 · Pull Request #10277 · stdlib-js/stdlib

InFiNiTy0639 · 2026-02-14T14:29:04Z

Progresses #649.

Description

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This pull request:

Progresses part of [RFC]: Add C implementations to base special math functions (tracking issue) #649 by adding lib/node_modules/@stdlib/math/base/special/log10f

Related Issues

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This Pull request:

Progresses [RFC]: Add C implementations to base special math functions (tracking issue) #649

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Open to reviews!!

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Read, understood, and followed the contributing guidelines.

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InFiNiTy0639 · 2026-02-14T18:28:24Z

@kgryte @Planeshifter Please Review this PR thanks

lib/node_modules/@stdlib/math/base/special/log10f/benchmark/benchmark.js

stdlib-bot · 2026-02-15T00:04:38Z

⚠️ Tracking Issue Closure Warning ⚠️

I noticed your PR description contains closing keywords ("Resolves", "Closes", or "Fixes") referencing a "Tracking Issue".

Why this matters:
Tracking issues should typically remain open until all related sub-issues are completed. GitHub automatically closes issues with such closing keywords when the PR is merged. For more information, see GitHub's documentation on using keywords in issues and pull requests.

Required action:
Use "Progresses" instead to reference the tracking issue without automatically closing it.

Thank you for your contribution to the project!

InFiNiTy0639 · 2026-02-15T04:43:13Z

⚠️ Tracking Issue Closure Warning ⚠️

I noticed your PR description contains closing keywords ("Resolves", "Closes", or "Fixes") referencing a "Tracking Issue".

Why this matters: Tracking issues should typically remain open until all related sub-issues are completed. GitHub automatically closes issues with such closing keywords when the PR is merged. For more information, see GitHub's documentation on using keywords in issues and pull requests.

Required action: Use "Progresses" instead to reference the tracking issue without automatically closing it.

Thank you for your contribution to the project!

@stdlib-bot Why did you add a potential duplicate module?, IN Issue #649 log10f packages implementation is still open

Removed unused variable declaration for options in benchmark. Signed-off-by: MA RIZWAN <148482027+InFiNiTy0639@users.noreply.github.com>

nakul-krishnakumar · 2026-02-15T04:56:26Z

@stdlib-bot Why did you add a potential duplicate module?, IN Issue #649 log10f packages implementation is still open

That is probably because there is already an open PR for log10f: #8873

InFiNiTy0639 · 2026-02-15T04:59:22Z

@stdlib-bot Why did you add a potential duplicate module?, IN Issue #649 log10f packages implementation is still open

That is probably because there is already an open PR for log10f: #8873

Yeah ,I also just checked this, but the PR is still not merged. I think I should work on other packages. 😢

Planeshifter

Thanks for opening a PR!

Planeshifter · 2026-02-15T03:47:26Z

lib/node_modules/@stdlib/math/base/special/log10f/src/main.c

+* @param x    input value
+* @return     output value
+*/
+float stdlib_base_log10f( const float x ) {


The parameter x is declared as const float, but it gets modified on line 70 (x *= TWO25) and line 83 (stdlib_base_float32_from_word(..., &x)). This will cause a compilation error.

I propose introducing a local float xc;, assign xc = x; near the top, and replace all subsequent uses of x with xc (see how lnf/src/main.c does it).

Planeshifter · 2026-02-15T03:47:33Z

lib/node_modules/@stdlib/math/base/special/log10f/lib/main.js

+function log10f(x) {
+    var hfsq;
+    var hi;
+    var lo;
+    var r;
+    var f;
+    var y;
+    var hx;
+    var i;
+    var k;
+
+    if (x === 0.0) {
+        return NINF;
+    }
+    if (isnanf(x) || x < 0.0) {
+        return NaN;
+    }
+    hx = toWord(x);
+    k = 0;
+    if (hx < FLT_MIN_NORMAL_EXP) {
+        // x < 2**-126
+        if ((hx & 0x7fffffff) === 0) {
+            return NINF; // log(+-0) = -inf
+        }
+        k -= 25;
+        x *= TWO25; // subnormal number, scale up x
+        hx = toWord(x);
+    }
+    if (hx >= FLT_MAX_EXP_BIT_MASK) {
+        return x + x;
+    }
+    if (hx === FLT_BIAS_EXP) {
+        return 0.0; // log(1) = +0
+    }
+    k += (hx >>> 23) - 127;
+    hx &= 0x007fffff;
+    i = (hx + 0x95f64) & 0x800000;
+    // Normalize x or x/2...
+    x = fromWord(hx | (i ^ FLT_BIAS_EXP));
+    k += (i >>> 23);
+    y = k;
+    f = x - 1.0;
+    hfsq = 0.5 * f * f;
+    r = kernelLog1pf(f);
+
+    hi = f - hfsq;
+    hx = toWord(hi);
+    hi = fromWord(hx & 0xfffff000);
+    lo = (f - hi) - hfsq + r;
+    return (y * LOG10_2LO) + ((lo + hi) * IVLN10) + (y * LOG10_2HI);


This is the most critical issue in this PR: the implementation is missing float64ToFloat32 wrapping around all arithmetic operations. In JavaScript, all math is performed in float64 by default. For a single-precision function, every intermediate computation must be explicitly rounded to float32 via float64ToFloat32(), or the results will be computed in double precision.

Take a look at how lnf/lib/main.js wraps every arithmetic expression in float64ToFloat32(...). For example, your line:

f = x - 1.0;

should be:

f = float64ToFloat32( x - 1.0 );

And:

hfsq = 0.5 * f * f;

should be:

hfsq = float64ToFloat32( 0.5 * float64ToFloat32( f * f ) );

This needs to be applied to every arithmetic expression in this function. You'll also need to add the float64ToFloat32 import at the top.

Planeshifter · 2026-02-15T03:47:38Z

lib/node_modules/@stdlib/math/base/special/log10f/lib/main.js

+var toWord = require('@stdlib/number/float32/base/to-word');
+var fromWord = require('@stdlib/number/float32/base/from-word');
+var isnanf = require('@stdlib/math/base/assert/is-nanf');
+var kernelLog1pf = require('@stdlib/math/base/special/kernel-log1pf');
+var NINF = require('@stdlib/constants/float32/ninf');


A few style issues here:

stdlib uses spaces inside parentheses for require calls: require( '...' ) not require('...'). This applies everywhere in the file.

The file uses 4-space indentation, but stdlib requires TAB indentation for .js files (per .editorconfig).

You're missing a float64ToFloat32 import, which you'll need for the correctness fix mentioned below.

Please also check the lnf package for the expected formatting -- it's the closest reference implementation.

Planeshifter · 2026-02-15T03:47:40Z

lib/node_modules/@stdlib/math/base/special/log10f/README.md

+
+@license Apache-2.0
+
+Copyright (c) 2018 The Stdlib Authors.


The copyright year should be 2025 for a new package, not 2018.

Suggested change

Copyright (c) 2018 The Stdlib Authors.

Copyright (c) 2025 The Stdlib Authors.

Planeshifter · 2026-02-15T03:47:43Z

lib/node_modules/@stdlib/math/base/special/log10f/test/test.js

+
+var tape = require('tape');
+var isnanf = require('@stdlib/math/base/assert/is-nanf');
+var isInfinitef = require('@stdlib/math/base/assert/is-infinitef');


isInfinitef is imported but never used. Please remove the unused import.

Also, all require calls in this file need spaces inside parentheses (e.g., require( 'tape' ) not require('tape')), and indentation should use tabs, not spaces.

Planeshifter · 2026-02-15T03:47:47Z

lib/node_modules/@stdlib/math/base/special/log10f/test/test.js

+tape('the function matches Math.log10 results within tolerance', function test(t) {
+    var expected;
+    var delta;
+    var tol;
+    var x;
+    var y;
+    var i;
+
+    for (i = 0; i < 100; i++) {
+        x = (Math.random() * 100.0) + 0.1;
+        x = float64ToFloat32(x);
+        y = log10f(x);
+        expected = float64ToFloat32(Math.log10(x));
+        delta = absf(y - expected);
+        tol = 2.0 * EPS * absf(expected);
+        if (tol < EPS) {
+            tol = EPS;
+        }
+        t.ok(delta <= tol, 'within tolerance. x: ' + x + '. y: ' + y + '. expected: ' + expected + '. delta: ' + delta + '. tol: ' + tol);
+    }
+    t.end();


Using Math.random() makes these tests non-deterministic -- they could pass on one run and fail on another. The stdlib convention is to use pre-generated test fixtures (typically from Julia or similar) stored as JSON files in test/fixtures/. Take a look at lnf/test/test.js for the expected pattern with fixture-based tests covering different value ranges (large positive, small positive, subnormal, etc.).

Planeshifter · 2026-02-15T03:47:49Z

lib/node_modules/@stdlib/math/base/special/log10f/examples/c/example.c

+#include <stdlib.h>
+#include <stdio.h>
+
+int main() {


stdlib convention uses int main( void ) instead of int main().

Suggested change

int main() {

int main( void ) {

Planeshifter · 2026-02-15T03:47:54Z

lib/node_modules/@stdlib/math/base/special/log10f/manifest.json

+            ]
+        }
+    ]
+}


This file is missing a trailing newline at the end, which is required by the project conventions. Same issue in package.json.

Planeshifter · 2026-02-15T03:47:56Z

lib/node_modules/@stdlib/math/base/special/log10f/benchmark/benchmark.js

+var bench = require('@stdlib/bench');
+var uniform = require('@stdlib/random/array/uniform');
+var isnanf = require('@stdlib/math/base/assert/is-nanf');
+var float64ToFloat32 = require('@stdlib/number/float64/base/to-float32');


float64ToFloat32 is imported but never used in this file -- it can be removed. Also, the same spacing/indentation style issues apply here (tabs, spaces inside parens).

feat: Add math/base/special/log10f

010161b

stdlib-bot added Math Issue or pull request specific to math functionality. First-time Contributor A pull request from a contributor who has never previously committed to the project repository. Needs Review A pull request which needs code review. labels Feb 14, 2026

nakul-krishnakumar reviewed Feb 14, 2026

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stdlib-bot added the Potential Duplicate There might be another pull request resolving the same issue. label Feb 15, 2026

InFiNiTy0639 changed the title ~~feat: Add math/base/special/log10f~~ feat: Add math/base/special/log10f Feb 15, 2026

Clean up benchmark.js by removing unused variables

4801f8d

Removed unused variable declaration for options in benchmark. Signed-off-by: MA RIZWAN <148482027+InFiNiTy0639@users.noreply.github.com>

InFiNiTy0639 changed the title ~~feat: Add math/base/special/log10f~~ feat: Add C implementation math/base/special/log10f Feb 15, 2026

stdlib-bot removed the Potential Duplicate There might be another pull request resolving the same issue. label Feb 16, 2026

InFiNiTy0639 mentioned this pull request Feb 16, 2026

fix lint errors test.dsyr2.js #10293

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Planeshifter requested changes Feb 17, 2026

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Planeshifter added Needs Changes Pull request which needs changes before being merged. and removed Needs Review A pull request which needs code review. labels Feb 17, 2026

	Copyright (c) 2018 The Stdlib Authors.
	Copyright (c) 2025 The Stdlib Authors.

+                          ]
+                      }
+                  ]
+              }

                
                    No newline at end of file

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InFiNiTy0639 commented Feb 14, 2026 •

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